The 57-year-old from Cheltenham in Gloucestershire was arrested for drug trafficking in May last year after police at Bali airport said they found almost 4kg of cocaine in the lining of her suitcase.

In January, she was sentenced by a district court to face a firing squad, even though prosecutors sought only a 15-year jail term.

During her trial, Sandiford said she was forced to carry the drugs by a gang who threatened to hurt her children. She lost an appeal to Bali's high court in April. Sandiford can still seek a judicial review of her case before appealing directly to the president for clemency.

A Foreign Office spokesman said: "We are aware that Lindsay Sandiford's appeal to the Indonesian supreme court has been denied. In line with our strong opposition to the death penalty in all circumstances, we will consider how to support any application for judicial review or clemency that Lindsay Sandiford chooses to make.

"We will continue to provide consular assistance to Lindsay Sandiford and her family at this difficult time."

Indonesian police say Sandiford was at the centre of a drugs ring involving three other Britons, all of whom have been convicted.

Julian Ponder, 43, was jailed for six years in January and fined the equivalent of £65,000 after being convicted of cocaine possession. His lawyers said he was told Sandiford was delivering a present for his child's birthday and, when he met her to receive the gift, police officers arrested him.

Ponder's partner, Rachel Dougall, 38, from Brighton, received a one-year jail sentence in March, She had been in jail for eight months awaiting trial and was freed in May. Paul Beales, a property developer and long-time Bali resident, was jailed for four years for possession of cannabis.